[1] Although most Central American magmas have a typical arc geochemical signature, magmas in southern Central America (central Costa Rica and Panama) have isotopic and trace element compositions with an ocean island basalt (OIB) affinity, similar to the Galapagos-OIB lavas (e.g., Ba/La < 40, La/Yb > 10, Pb/Pb > 18.8). Our new data for Costa Rica suggest that this signature, unusual for a conve...

ABSTRACT The integration of biostratigraphical, wireline log, geophysical and available geochronological ages has identified two principal periods volcanism in the Faroe–Shetland Rockall basins. first is pre-breakup, upper Danian to lower Thanetian: basins, isolated volcanic activity from 62 Ma 58.7 areas closely linked SSW–NNE structural fabric continental margin. Volcanic was concentrated at ...

The adiabatic transit time of wave energy radiated by an Agulhas ring released in the South Atlantic Ocean to the North Atlantic Ocean is investigated in a two-layer ocean model. Of particular interest is the arrival time of baroclinic energy in the northern part of the Atlantic, because it is related to variations in the meridional overturning circulation. The influence of the Mid-Atlantic Rid...

A substantial amount of subducted basaltic crusts may exist in the lower mantle. It features distinct chemical composition from peridotitic mantle and plays important roles dynamic evolution Earth's interior. However, mineral phases present crust is still poorly constrained. Here, we determined phase relations normal mid-ocean ridge basalt (MORB) up to 52 GPa at 2000 K by multi-anvil press. Thr...

We measured Ni partitioning between olivine and melt, D Ni , in experiments on mid-ocean ridge basalt (MORB) encapsulated in olivine at pressures from 1atm to 3·0 GPa and temperatures from 1400 to 15508C.We present a series of experiments where the temperature (T) at each pressure (P) was selected so that the liquid composition remained approximately constant over the entire P^T range.This appr...

The tree of terrestrial life probably roots in non-photosynthetic microbes. Chemoautotrophs were the first primary producers, and the globally dominant niches in terms of primary productivity were determined by availability of carbon dioxide and hydrogen for methanogenesis and sulfite reduction. Methanogen niches were most abundant where CO 2 -rich ocean water flowed through serpentinite. Black...

Abstract During the middle Miocene, forearc alkaline magmatism occurred in Outer Zone of Southwest Japan and northern Ryukyu Arc, resulting formation basaltic rocks with ocean island basalt (OIB)-like chemical signatures. In contrast, subduction-related was present central Arc. However, southwestern margin poorly constrained We examined two dikes Chichibu accretionary complex Amami-Oshima Islan...